Although food consumption is a component of lifestyle that is of great importance to health, little is known about the processes that determine patterns of food consumption during adolescence. Social Psychology and closely connected disciplines provide theoretical perspectives on eating behavior, and their application to adolescent eating may promote more healthful food choices. Adolescents' food choices have been described but not adequately explained in previous research, and the simultaneous examination of cognitive, developmental, social, and environmental factors should assist in generating a comprehensive theoretical framework for adolescetn eating behovior. Research is proposed in which five kinds of data will be collected from 400 adolescents, aged 11-12 and 15-16. First, cognitive development and personality variables will be assessed. Second, measures will be taken of height, weight and skinfold thickness; self-perception of body weight; cosial class, race and ethnicity. Third, each subject will describe his or her decision-making processes in food choice. Fourth, subjects will complete questionnaires to provide ratings of foods in terms of possible criteria for food choice. Fifth, several telephone calls will be made to each subject to obtain repeated measures of foods eaten in the previous 24-hour periods. A preliminary study of 50 students will pilot test these measures for their final version for the sample of 400. Data analyses will test a series of hypotheses derived from a proposed Social Psychological model of food choice. The findings should provide information useful in the design of programs for education and behavior change in nutrition. The significance of the research is magnified by the fact that patterns of adolescent eating tend to persist into adulthood, and the long-term consequences of eating behavior may involve diseases related to lifestyle such as heart disease, diabetes, hypertension, and cancer.